1. Field of the Invention
The present invention relates to a communication system, communication apparatus and control method thereof, appropriate for application in, for example, a wireless television system.
2. Description of Related Art
In recent years, a new type of television system where a base station provided with a television broadcast tuner function and an internet connection function and a monitor provided with a liquid crystal panel and speaker are provided separately has come into being (for example, refer to non-patent document 1).
With this kind of television system (in the following, this is referred to as a wireless television system), a base station and a monitor are connected together by a wireless LAN (Local Area Network) conforming to, for example, IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard. The received audio-visual data of television broadcasts and homepage image data etc. downloaded from the Internet etc. in the base station are transmitted in a wireless manner to the monitor. It is then possible to enjoy television broadcasts etc. all around the house no matter where a user is by displaying images and outputting audio at a monitor based on this audio-visual data and image data.
[Non-Patent Document 1]
Airboard, (online), Sony Corporation, Nov. 25, 2003, Internet URL: http://www.sony.jp/products/consumer/airboard
In this wireless television system, a base station and monitor are respectively provided with power supply switches so that the base station and monitor may be turned on and off independently through operation of these power supply switches.
However, with this wireless television system, turning on and off of the base station is completely independent and control of a power supply of the base station from a remote location is not possible. It is therefore necessary for a user to actually go to the base station every time and turn off a power supply switch in order to put the base station into a complete low power consumption state (hereinafter referred to as standby mode). This may make the wireless television system less convenient.
A system capable of turning the power supply of the base station off as a result of remotely operating the monitor as a remote controller by utilizing, for example, a communication function of the wireless television system has been considered as one method for resolving this issue.
However, in this method, a communication between the base station and the monitor is cut if a power supply of a base station is turned off. There is an issue where a power supply of a base station cannot be turned on even if a power supply of a base station can be turned off using a monitor.
In this event a configuration is adopted for a system where, for example, just a communication function is made to continue to function if the power supply of the base station is turned off, and the power supply of a base station is turned on if a message instructing to turn the power supply on is received in response to a user operation.
With this kind of wireless television system, as described above, a connection that is made between a base station and a monitor is wireless via a wireless LAN conforming to the IEEE 802.11 standard. If a communication function of a base station functioning as an access point of the IEEE 802.11 standard is made to remain functioning, electromagnetic radiation referred to as a beacon containing identification information (SSID (Service Set Identification)) and information relating to encryption at the time of communication is periodically transmitted from the base station over it's own wireless LAN.
In other words, information may be intercepted by a malevolent third party so that information relating to SSID and encryption for the base station and monitor may be misappropriated. This may enable communication between the base station and the monitor to be intercepted thereafter and means that there is a danger of illegal accesses to the Internet via the base station. Accordingly, it may not be possible to maintain a highly secure environment.
In order to take into consideration the aforementioned points, it is advantageous for the present invention to provide a communication system, communication apparatus and control method capable of improving convenience for a user while maintaining a highly secure environment.